Presser-foot-lifting mechanism for sewing-machines.



w. L. BARRON & F. E. 0301. PRESS ER FOOT LIFTING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAY I7, 1915.

Patented June 18, 1918.

WITNESSES.

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"WILLIAM L, BARRON, OF NEW YORK, 1\T. AND FRITZ E. OSOL, OF ELIZABETH, NEW JERSEY, ASSIGNOBIS TO THE SINGIEB/ MANUFACTURING COMPANY, A CORPORATION OF NEW J JERSEY.

PRESSlEB-FOOT-LIFTING MECHANISM FOR SEWING-MACHINES.

To all whom it may concern: Be it known that we, WILLIA L. and FRITZ E. Oso citizens of the United States, residing, respectively, at NewYork, in the county of New York and State of New York, and Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Presser-Foot-Lifting Mechanisms for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to, presser-foot lift ing mechanism for sewing machines and especially machines in which the work is advanced between successive stitches, as in the operations of darning and patching.

It is common. to the art to'provide means adapted to automatically lift the presserfoot at intermittent periods, and thepresent improvements comprise special presser-foot lifting means adapted to obviate the sudden contact of certain parts and consequent shock when the presser-bar is released at the completion of the lifting movement thereof.

In the preferred embodiment of the improvements, as herein illustrated, a split collar is fitted upon the presser-bar, one portion of the collar carrying a roller-stud fitted within the cam-slot of a cam-plate fulcrumed upon the collar in such position that when it is turned the walls of its camslot act upon the roller-stud to clamp the collar firmly. upon the bar preparatory to a lifting movement. The needle-bar is employed to lift the presser-bar, and to such end it is provided with a collar having a link connection with a cam-plate. A spring surrounds the presser-bar and exerts a downward pressureon the split collar, so thatthe upward movement of the needle-bar first rocks the cam-plate upon its fulcrum to clampthe split collar upon' the presser-bar and secondly lifts the presser-bar against the action of its spring; :A tappet arm fulcrumed on .theframe has a link connection withthe cam-plate and thisis caused to follow the turning and bodily upward movements of the latter. Thi tappet arm serves as a stop to limit the downward movement of the clamping elements and, when the parts: reach their lower positlon, the camplate is turned to release the presser-bar.

Specification of Letters Patent.

Application filed May 17, 1915. Serial No. 28,513.

BARRON:

Patented June its, 119th.

' It will thus be seen that the link connection between the tappet arm and the cam-plate prevents any sudden contact and consequent shock betweenthese parts. The downwardmovement of the collar ceases just as the presser-foot reaches the work, and the turning movement of the disk thereafter releases the presser-bar, so that the momentum of the latter is largely absorbed before it. is released, and the foot gives a slight blow only to the work and throat-plate.

In the drawings, Figure 1 is a front elevation of the improvements applied to a sewing machine and Fig. 2 is a plan view, partly in section, of the same. Fig. 3 is a perspective view of the needle-bar, the presser-bar, and certain connections. Fig. 4 is a perspective view, partly in section, of the cam-disk and its connections, and Fig. 5 is a rear elevation of the cam-disk and its connections.

The improvements are shown applied to a sewing machine comprising the bed A,

standard B and overhanging head C, the latter being formed with suitable bearing apertures for the needle-bar 1, and the presser-bar 2 carrying the foot 2". Loosely fitted upon the presser-bar is a collar 3 split at 3? and formed with a threaded aperture at 1, to receive a stud-screw 5 serving as a fulcrum for a cam-plate comprising the members 6 and 63* secured together by means of the screws 7. The section 6 of the camplate is formed with the cam-slot 8 adapted to receive the roller-stud 9 carried by a plate 10 secured by means of the screws 11 to that portion of the collar opposite the threaded aperture 4:. I

The needle-bar is employed to lift the Presser-bar at the proper time. To this end a collar 12 is fixed upon the needle-bar and a link 13 connects the collar with the camplate at 14. The presser-bar is pressed downwardly by the usual plate spring 15, and surrounding the resser-bar is a coiled spring 16 which presses upon the upper face of the split collar 8. Thus when the needlecollar and presser-bar to lift the presser-foot above the Work.

Fulcruined atfll'7 upon a bracket 18 secured to the head C by means ofthe screws Thereby on the downward Inoyement 8f the needle noise and shock due to reciprocating pa rt'sjis diminished if int altogether avoided. In operation as the needle descends from it's raised position, Fig. 1, to the'clothplate the split collar, together with" the camplate 6 move bodily downi'var'd and link 21 turnstappet 20 about pivot 17 There is a very slight rotation of cam-plate 6 about its p iv'ot at this time. Then, before the'ne'e'dle and passer-root reaoh the inatei'ialand because of the retarding action of tappet 20 'on surface caih 6 the ca rn-plate 6 is tnr'ne'd siii'licieiitly about it's pivot 5 to release the grip of thesplit 'collar on the. presser-ba'r and to permit the presser-fo'ot to engage the material being operated upon at about the time the needle reaches the goods. It Will be "noted that when release of the Presserbar secure, the'foot Will be thrust downward only by leaf-spring 15, the pressure of'wl'iich may obviously beni'ade as light or heavy as desirable. After the press'erbaiis released from the collar the Weight of the parts bp'erating the latter is largely carried by the 'c'ol- Mr 12 fast to the needle-bar. In this condition the operating devices constitute a floating liiikageslidingly connected to the vertical Presser-bar. It is to be further noted that the shape of the upper face of the tappet 20 and the edge of the surface cam 6 secured to the earn 6 with which the tappet engages, is such that when the'presser-foot is engaged with the material the split *c'ol- 'lar"3 moves downwardly very little in'proportion to the downward movement of the needle, thereby avoiding the shock and'vi ear inseparable from rapidly moving reciprocating parts.

Because of this action the tappet arm 20 inay be described as a retarding device for it acts to slow down the bodily vertical intoveinent of the presser-bar very slightly as the'needl'e-bar descends'froin its raised position but sufliciently to compel rotation ofcarn-plate 6 whereby the presser bar'is released. Thereafter the'tappet arm 20 is raised slightly as thetoggle link 21 passes over the line of 'c'enterstof the pivot -'5 and the pivotal connection of 'link :21 Witht2Lp pet arm 20 Which; elevation ofthe tappet arm materially retards the downward movement of split collar3and its operatin -links.

' The shape and arrangement of applicants both in gripping and releasing the bars when used with a split collar which is adapted to be etinstricted about the presserbar in the manner of action found in a handbrake, the leading characteristic of which has'ibeen utilized in applicants device.

It Will be understood that various changes may he hiade in tlie ior'm and arrangement of the various elements herein shown and describedu ithotit departing from the spirit of the invention. For example the camplat e sections 6 and B 'may be made integral, and means other than the link 13 may be employed to connect the cam-plate with the needle-ban Ha-viiig'thus set forth the nature of the invention, What We claim herein is 1. Ina Presser-foot lifting mechanism, the combination ivith a Presser-bar, and a needle-bar, of a split collar embracing the 3re'sse1"bar, a link'connected to the needlear, and a cam-plate pivoted to the collar at one side of the split and operable on the collar directly on the other side of the split to circumferentially constrict and grip the split 'collar like a band about the presscr=bar.

2. In pressei foot lifting mechanism, the eoinbina'ti'on with a recipr'o'c'atory actuz'tting member, a p'resser bar, and a 'collar surrounding the bar, of a rocking and bodilyn'iovable lever adapted to 'constrict said collar, a connection between said lever and the recipro'catory actuating i'n'eniber, and a retarding device for the collar \vhereby the 'doi'vnward moveinent of the presser-bar is retarded for an interval imn'rediately preceding its' rele'ase.

3. In a sewing machine, the combination with a presser-bar and ahu'eed'le-bar of a split collar embracing the presser-bai', a cam-plate pivoted upon; the collar and adapted to constri'ct the same about t'hepresse'r- 'bar, a link connecting the canl-plate and the needle-bar, "a tappet arm fincrumed upon the frame, and a link connection between the tappet arm and the cam-plate.

4. The combination with a presser-bar and "a split collar embracing thesa me and carrying a stud, of a cam-plate pivoted upon the collar and adapted to act upon the stud to eonstrict the collar, and means for turning said plate upon its-pivot to constriot the collar and subsequently imparting a bodily upward movement thereto.

. 5. In a sewing machine, the combination shat andcarrying astud, 'a cam-plate pivoted t lt dli

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naeema upon the collar and adapted to act upon the stud to constrict the collar, a link connecting the cam-plate and the reciprocatory member, a tappet-arm fulcrumed upon the frame, and a link connection between the tappet-arm and the cam-plate.

6. In a resser-foot lifting mechanism, the combination with a reciprocatory actuating member, a presser-bar, and a split collar surrounding the bar, of a rocking and bodily ,movable camlate adapted to constrict said collar upon t e presser-bar, and carrying a surface cam, a connection between said camplate and the reciprocatory actuatingmemher, and a retarding device for the collar and its actuating parts whereby the downward movement thereof relative to the needle is materially diminished, said retarding device including an arm in sliding and rolling engagement with said surface cam secured to the rocking and bodily movable cam-plate.

7. In a presser-foot lifting mechanism, the combination with a reciprocatory actuating member, a presser-bar, a split collar surrounding the bar, of a rocking and bodily movable cam member adapted to intermit tently constrict said collar about said presser-bar, a connection between said cammember and said reciprocatory actuating member, and a retarding device for the collar, whereby the downward movement of the collar and its actuating mechanism is retarded, said device including a toggle link.

8. In a presser-foot lifting mechanism, the combination with a reciprocatory actuating member, a resser-bar, a split collar surrounding the bar, of a rocking and bodily movable cam member adapted to intermittently constrict said collar about said presser-bar, a connection between said cam member and said reoiprocatory actuating member, a retarding device for the collar, whereby the downward movement of the collar and its actuating mechanism is retarded, said retarding device including a toggle link and a tappet-arm pivoted to the frame of the machine and connected to said toggle link, said toggle link being also connected to said rocking and bodily movable cam member.

9. In a presser-foot lifting mechanism for sewing machines having stitch-forming mechanism including a needle and a head carrying the same, in combination, a presserbar, a band-like. member encircling the resser-bar, said member being split at one point in its circumference, and means at the opposite ends of said band adjacent said split for circumferentially approaching said ends to cause the member to grip the bar, said means including a linkage entirely inclosed within the outline of the head.

10. In a presser-foot lifting mechanism for sewing machines havin stitch-forming mechanism including a nee Is, in combination, a presser-bar, a band-like member encircling the pressenbar, said member being split at one point in its circumference, means at the opposite ends of said band adjacent said split for circumferentially approaching said ends to cause the member to grip the bar, means for lifting said presser-foot simultaneously with the needles including a toggle-actuated retarding device for lowering the presser-foot at a slower speed than the needle.

11. In a presser-foot lifting mechanism for sewing machines having stitch-forming mechanism including a needle, in combination, a- Presser-bar, a band-like member encirclin the presser-bar, said member being sp it at one point in its circumference, means at the opposite ends of said band adjacent said split for circumferentially approachin said ends to cause the member to grip the ar, and positive means for lowering the presser-foot to a position substantially on the work and releasing it.

12. In a sewing machine for darning and having stitch-forming mechanism including a needle in combination, a springpressed presser-bar, a presser-foot carried thereby, means for intermittently clamping said bar, said means acting positively to lower the presser-foot to a position substantially in contact with the material and then releasing the Presser-bar to permit the foot to impinge against the material under the action of its own spring.

In testimony whereof, we have signed our names to this specification.

FRI'JM 1E. OSOL.

Copies of this patent may be obtained for tlve cents each, by addreamlnn the "flommltaloner of Patents,

Washington, n. t.

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